A Santa Rosa couple who lost their home in the deadly fires that tore through Sonoma County last week filed a lawsuit Tuesday blaming PG&E for the blaze.

The lawsuit is the first against the utility company for its possible involvement in the North Bay fires and comes even before investigators have determined what caused the deadly fires.

But Wayne and Jennifer Harvell say their lawsuit is the beginning of an attempt to figure out what happened.

“We lost everything,” said Jennifer during a phone interview. “We lost our lives. So did everyone we know in our neighborhood, and, basically, we want to find out the truth about this.”

The Harvells allege that the utility company failed to adequately maintain power lines, leading to the destruction of their Coffey Park house and at least 1,000 others in the neighborhood as the Tubbs fire consumed the region.

The Harvells had lived in Santa Rosa for more than three decades before the blaze turned their home on Mocha Lane just west of Highway 101 to ash. They hope the lawsuit, filed in San Francisco Superior Court, will prompt PG&E to maintain its equipment and prevent similar fires in the future, they said.

Bill Robins, their lawyer, said the suit will put PG&E employees on notice that they need to preserve evidence, including any emails, related to the fires.

As this news organization reported last week, Sonoma County emergency dispatchers received multiple calls of electrical transformers exploding and power lines falling in heavy winds, raising questions about PG&E’s maintenance of power lines and whether it cleared vegetation to reduce the risk of fire.

The power lines are only one of the many factors investigators from Cal Fire and the state’s Public Utilities Commission (PUC) are looking into as they search for the cause of the fire. Officials say it’s too early to determine the cause of the fires that started on Oct. 8 — a warm, dry, windy Sunday night — and spread into Santa Rosa neighborhoods early Monday morning.

The regulatory agency has already sent a letter to the utility ordering it to preserve any equipment possibly related to the fires and internal communications discussing the disaster.

In an emailed statement, Angela Lombardi, a PG&E spokeswoman, said, “As the fires continue to burn, we’re focused on supporting firefighting efforts to contain the fires and protect life and property. Once it is safe to do so, restoring power and gas service safely and as quickly as possible will be our priority. We aren’t going to speculate about any of the causes of the fires and will cooperate with the reviews by any relevant regulator or agency.”

While the Harvells’ suit is the first against PG&E related to the Wine Country fires, legal experts expect other families to file additional lawsuits against the company in the coming weeks and months.

“No question there’s going to be a large number of cases filed behind this,” Robins said. “We represent a number of other people already and are fielding calls quite frequently on a day-to-day basis.”

In a separate suit unrelated to the fires filed Wednesday, San Francisco City Attorney Dennis Herrera sued PG&E to recover the costs, around $8 million so far, from a landslide that destroyed a home and damaged five others he says was caused by the company’s negligence.

PG&E has $800 million in liability insurance but estimates for fire damages are ranging as high as $3 billion already, which could affect the company’s financial stability.

In the days after the fire started, the company’s stock declined to $53.43 on Monday from $69.15 just a week ago as people questioned the company’s liability. The share price had rebounded somewhat to $56.77 on Wednesday.

In 2015, regulators fined the company $1.6 billion for the deadly 2010 San Bruno pipeline explosion. Federal investigators said flawed record-keeping by the company and poor maintenance caused the inferno. The PUC also fined PG&E more than $8 million for the Butte fire, which burned nearly 550 homes in Amador County and killed two people in 2015.